Fig. 4.

Introduction of AP-cav restores Mn²⁺-quenching of fura-2 fluorescence in the continued presence of luminal ATP (20 μM) in isolated small pulmonary arteries from CH rats. Percent change in fura-2 fluorescence at 360-nm excitation where trace data are expressed as means in the presence of AP-scrambled peptide (A) and AP-cav (B). C: fura-2 quench rate (initial decline) expressed as percent change during the first 60 s after addition of 500 μM Mn²⁺. D: quench values (during the final min) represented as percent change relative to baseline at 360 nm. Experiments were performed at the estimated in vivo pressures for control (12 mmHg) and CH (35 mmHg) arteries. Values are means ± SE; n =4–6 rats/group. *P ≤ 0.05 vs. control and **P ≤ 0.05 vs. CH AP-scrambled.